1. Field of the Invention
The invention relates to a wood planing machine, more particularly to a wood planing machine provided with a cutter locking device for locking a cutter unit when the cutter unit is at a non-operative state.
2. Description of the Related Art
Referring to FIG. 1, a conventional wood planing machine is shown to include an elongated machine base 10, first and second pairs of posts 100, a cutter carriage 11, vertical first and second threaded rods (not visible), carriage fastening means, an elongated cutter unit 12, and a cutter locking device 17.
As illustrated, the machine base 10 has opposed first and second mounting sides spaced apart from each other in a longitudinal direction, and opposed feed-in and take-out sides spaced apart from each other in a transverse direction. The first and second pairs of posts 100 are fixed on the machine base 10 at the first and second mounting sides, respectively.
The cutter carriage 11 is disposed above the machine base 10, and has first and second end portions 110 mounted respectively, vertically and movably on the first and second pairs of posts 100 for moving the cutter carriage 11 along the posts 100, thereby adjusting height of the cutter carriage 11 relative to the machine base 10.
The carriage fastening means fastens releasably the carriage 11 on the first and second pairs of posts 100 after adjusting the height of the carriage 11 relative to the machine base 10.
The cutter unit 12 is disposed to extend in the longitudinal direction, and has first and second shaft portions 120 journalled to the first and second end portions 110 of the cutter carriage 11.
The cutter locking device includes an inverted L-shaped locking member 17 mounted pivotally on an outer surface of the second end portion 110 of the cutter carriage 11 above the second shaft portion 120 via a pivot pin 171, a pair of engagement grooves 121 formed in an outer surface of the second shaft portion 120 in a radial direction, and a biasing unit 18 which biases a first arm portion 172 of the locking member 17 to rotate about the pin 171 in a direction in such a manner that an engaging tongue 173 of a second arm portion 174 engages one of the engagement grooves 121 in the cutter unit 12, thereby preventing rotation of the cutter unit 12 relative to the carriage 11 and disposing the cutter unit 12 at a locked position.
The cutter carriage 11 further includes a waste passage 15 formed in an outer surface of the second end portion 110 thereof at an elevation above the second shaft portion 120, and a waste collection member 16 which is inserted removably into the waste passage 15 for guiding waste that results from operation of the cutter unit 12 and which presses the first arm portion 172 of the locking member 17 against biasing action of the biasing unit 18, thereby removing the engaging tongue 173 from the engagement groove 121 and correspondingly permitting rotation of the cutter unit 12 relative to the cutter carriage 11, and disposing the cutter unit 12 at an unlocked position.
One disadvantage that results from the use of the aforesaid conventional wood planing machine resides in that the locking member 17 is mounted pivotally on the carriage 11, thereby affecting adversely the locking effect thereof.